Spring MVC, load objects attributes in a jsp - spring

I got an issue when trying to load an object attribute in a jsp file.
The model contains a list of objects of type "Evaluation", for each element in the list, all the attributes are correctly loaded except the ones that it has to fetch from another table.
The .jsp file :
<div class="container">
<h1>Liste des Evaluations pour ${etudiant.username}</h1>
<table class="tbl">
<thead>
<th>Module</th>
<th>Note</th>
<th>Remarque</th>
</thead>
<tbody>
<c:forEach items="model.evaluations" var="ev">
<tr>
<td>${ev.examen.module.code}</td> --> Error occurs here
<td>${ev.note}</td>
<td>${ev.remarque}</td>
</tr>.
</c:forEach>
</tbody>
</table>
The Controller :
#RequestMapping(value="/{username}", method=RequestMethod.GET)
public String etudiantEvaluations(
#PathVariable String username, Model model) {
List<Evaluation> evaluations = evalDAO.findAllByEtudiant(username);
Etudiant etudiant = etDAO.findByUsername(username);
model.addAttribute("evaluations", evaluations);
model.addAttribute("etudiant", etudiant);
return "etudiants/listEvaluations";
}
The Evaluation entity :
#Data
#NoArgsConstructor
#EqualsAndHashCode
#Immutable #Entity(name="TEVALUATION")
public class Evaluation {
private enum evaldeliberation {
REUSSITE,
AJOURNEMENT,
REFUS,
ABANDON
}
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
protected Long id;
#NotNull
#Min(0) #Max(100)
#Column(updatable = true)
private Double note;
#Column(name="deliberation")
private evaldeliberation delib;
#Column(name="remarque")
private String remarque;
#Column(name="module_code")
private String moduleCode;
private Long examenId;
private String etudiantUsername;
#ManyToOne(fetch=FetchType.EAGER)
#JoinColumn(name = "FKExamen",
insertable = false,
updatable = false)
protected Examen examen;
#ManyToOne
#JoinColumn(name = "FKEtudiant",
insertable = false,
updatable = false)
protected Etudiant etudiant;
#OneToMany(mappedBy="evaluation")
protected List<EvalComp> evalComps = new ArrayList<>();
public Evaluation(Double note, Examen examen, Etudiant etudiant) {
super();
this.examen = examen;
this.etudiant = etudiant;
examen.getEvaluations().add(this);
etudiant.getEvaluations().add(this);
}
}
Examen:
#Data
#EqualsAndHashCode
#NoArgsConstructor
#Entity(name="TEXAMEN")
public class Examen {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#OneToMany(mappedBy = "examen")
private Set<Evaluation> evaluations = new HashSet<>();
#NotNull
#OneToOne(cascade=CascadeType.PERSIST)
#JoinColumn(name="FKmodule")
protected Module module;
public Examen(Module module) {
this.module = module;
}
}
The Query:
#Query("SELECT ev FROM TEVALUATION ev JOIN FETCH ev.examen ex JOIN FETCH ex.module m WHERE ev.etudiant=?1")
List<Evaluation> findAllByEtudiantId(String username);
The getters and setters are generated by Lombok(also tried without it).
Any idea how can I load the attributes ?
Thanks in advance.

Related

EL1007E: Property or field 'name' cannot be found on null

I am using a Spring framework with thymeleaf and mysql.
I am getting the error
org.springframework.expression.spel.SpelEvaluationException: EL1007E: Property or field 'name' cannot be found on null
This error is being caused by the ${selectProject.client.name} in the html code.
I have written a form to allow a user to add information about a project. As part of the form, there is a dropdown list of the different project names. However, in the dropdown list I also want it to give the name of the client alongside the name of the project.
My html code:
<form action="#" id="informationForm" method="post" th:action="#{/add-information}" th:object="${information}">
<div class="row">
<div class="form-group col-12">
<label class="col-form-label" for="project">Project</label>
<select class="form-control" id="project" th:field="*{project}">
<option value="0">Please select a project</option>
<option th:each="selectProject : ${projectList}"
th:text="${selectProject.client.name} + ' - ' +${selectProject.name}"
th:value="${selectProject.id}"></option>
</select>
Here is the information controller:
#Controller
#Slf4j
#SessionAttributes({"project", "information"})
public class InformationController {
private final InformationService informationService;
private final ProjectsService projectsService;
#Autowired
public InformationController(final ProjectsService projectsService,
final InformationService informationService) {
this.projectsService = projectsService;
this.informationService = informationService;
}
#ModelAttribute("information")
public Information getInformation() {
return informationService.createEmptyInformation();
}
#ModelAttribute("projectList")
public List<Project> getProjects() {
return projectsService.getProjects();
}
#GetMapping("add-information")
public String showAddInformationForm(Model model, #ModelAttribute("information") Information information) {
information = informationService.createEmptyInformation();
model.addAttribute(information);
return "add-information";
}
#PostMapping("add-information")
public String addInformationForm(#Valid Information information, BindingResult result, Model model) {
if (result.hasErrors()) {
return "add-information";
}
Long id = informationService.createInformationFromInput(information);
return "redirect:/homepage";
}
The relevant methods in the information service are:
public Information createEmptyInformation() {
return new Information();
}
public Long createInformationFromInput(Information information) {
try {
informationDao.save(information);
} catch (Exception ex) {
log.error("Failed to save information for {} because of {}", information.getId(), ex.getLocalizedMessage());
}
return information.getId();
}
and in the projects services:
public List<Project> getProjects() {
return projectDao.findAll();
}
Clients have a many to one relationship with projects
Project domain:
#Getter
#Setter
#Entity
#Table(name = "projects")
public class Project {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "client_id")
private Client client;
#Column(name = "name")
private String name;
Client domain:
#Getter
#Setter
#Entity
#Table(name = "clients")
public class Client {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotBlank(message = "Name is required")
#Size(min = 5, max = 80, message = "Name must be between 5 and 80 characters")
#Column(name = "name", nullable = false)
private String name;
#OneToMany(fetch = FetchType.LAZY)
#JoinColumn(name = "client_id")
#JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
private List<Project> projects;
Information domain:
#Getter
#Setter
#Entity
#Table(name = "information")
public class Information {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#ManyToOne (fetch = FetchType.LAZY)
#JoinColumn(name = "project_id")
private Project project;
#Column(name = "date")
private Date date;

Changes not persisted in database in a Spring Boot application using Spring JPA

I have a Spring Boot application that needs adds a post to a feed list. A post is written by a user and consists of a content and several attachments. The database has 3 tables: post, attachment and user.
The main class of the application is:
#SpringBootApplication
public class SocialMediaApplication {
public static void main(String[] args) {
SpringApplication.run(SocialMediaApplication.class, args);
}
}
The entities are the following:
Post.java
#Entity
public class Post implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#Column(nullable = false)
private String content;
#ManyToOne
#JoinColumn(name = "user_id")
private User user;
#Column(nullable = false)
private Timestamp createdAt;
#Column
private String location;
#OneToMany(mappedBy = "post", cascade = CascadeType.ALL)
private List<Attachment> attachmentList;
#OneToMany(mappedBy = "post", cascade = CascadeType.ALL)
private List<Rating> ratingList;
public Post() {
}
public Post(String content, User user, Timestamp createdAt, String location, List<Attachment> attachmentList, List<Rating> ratingList) {
super();
this.content = content;
this.user = user;
this.createdAt = createdAt;
this.location = location;
this.attachmentList = attachmentList;
this.ratingList = ratingList;
}
// ...
}
Attachment.java
#Entity
public class Attachment implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#Lob
#Column(length = 100_000, nullable = false)
private byte[] content;
#ManyToOne
#JoinColumn(name = "post_id")
private Post post;
public Attachment() {
}
public Attachment(byte[] content, Post post) {
super();
this.content = content;
this.post = post;
}
// ...
}
User.java
#Entity
public class User implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue
private Long id;
#Column(nullable = false)
private String firstName;
#Column(nullable = false)
private String lastName;
#Column(nullable = false)
private Date dateOfBirth;
#Column(nullable = false)
private String credential;
#Column(nullable = false)
private String password;
#Column
private String location;
#Lob
#Column(length = 100_000)
private byte[] photo;
#Column
private String motto;
public User() {
}
public User(String firstName, String lastName, Date dateOfBirth, String credential, String password,
String location, byte[] photo, String motto) {
super();
this.firstName = firstName;
this.lastName = lastName;
this.dateOfBirth = dateOfBirth;
this.credential = credential;
this.password = password;
this.location = location;
this.photo = photo;
this.motto = motto;
}
// ...
}
All repositories extend CrudRepository and are annotated with #Transactional:
PostRepository.java
#Transactional
public interface PostRepository extends CrudRepository<Post, Long> {
}
AttachmentRepository.java
#Transactional
public interface AttachmentRepository extends CrudRepository<Attachment, Long> {
}
UserRepository.java
#Transactional
public interface UserRepository extends CrudRepository<User, Long> {
}
The controller that should add a post to the feed is the following:
#Controller
#RequestMapping("/post")
public class PostController {
#Autowired
PostRepository postRepository;
#GetMapping("/add")
public String greetingForm(Model model) {
model.addAttribute("post", new Post());
return "addPost";
}
#PostMapping("/add")
public String addPost(#ModelAttribute Post post, #RequestParam("attachment") MultipartFile uploadingFile) throws IOException {
User user = new User();
user.setId(1L);
post.setUser(user);
post.setCreatedAt(Timestamp.valueOf(LocalDateTime.now()));
List<Attachment> attachmentList = new ArrayList<>();
Attachment attachment = new Attachment();
attachment.setContent(uploadingFile.getBytes());
attachment.setPost(post);
attachmentList.add(attachment);
post.setAttachmentList(attachmentList);
List<Rating> ratingList = new ArrayList<>();
post.setRatingList(ratingList);
postRepository.save(post);
return "allPosts";
}
}
The addPost.html page has the following content:
<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<title>Add Post</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<h1>Add Post</h1>
<form action="#" th:action="#{/post/add}" th:object="${post}" method="post" enctype="multipart/form-data">
<table border="0">
<tr>
<td>Content</td>
<td><textarea id="content" th:field="*{content}" rows="5" cols="50"></textarea></td>
</tr>
<tr>
<td>Location</td>
<td><input type="text" id="location" th:field="*{location}"/></td>
</tr>
<tr>
<td>Attachment</td>
<td><input type="file" id="attachment" name="attachment"/></td>
</tr>
<tr>
<td colspan="2">
<input type="submit" value="Submit" />
<input type="reset" value="Reset" />
</td>
</tr>
</table>
</form>
</body>
</html>
The application.properties file has the following content:
spring.datasource.url=jdbc:mysql://localhost:3306/****?useSSL=false
spring.datasource.username=root
spring.datasource.password=****
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.properties.hibernate.id.new_generator_mappings=false
spring.jpa.show-sql=true
spring.thymeleaf.cache=false
spring.thymeleaf.enabled=true
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.suffix=.html
However, when I press the submit button, nothing is persisted into the database, although the queries are being displayed in the console:
Hibernate: insert into post (content, created_at, location, user_id) values (?, ?, ?, ?)
Hibernate: insert into attachment (content, post_id) values (?, ?)
What could be the cause?

Thymeleaf: print a Set in the template

I have a basic SpringBoot 2.0.4.RELEASE app. using Spring Initializer, JPA, embedded Tomcat, Thymeleaf template engine, and package as an executable JAR file.
I have this entity:
#Entity
#Table(name="t_user")
public class User implements Serializable, UserDetails {
#OneToMany(mappedBy = "user", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
#JsonIgnore
private Set<UserRole> userRoles = new HashSet<>();
public Set<UserRole> getUserRoles() {
return userRoles;
}
public void setUserRoles(Set<UserRole> userRoles) {
this.userRoles = userRoles;
}
}
and this:
#Entity
#Table(name = "t_user_role")
public class UserRole implements Serializable {
/** The Serial Version UID for Serializable classes. */
private static final long serialVersionUID = 1L;
public UserRole() {
}
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private long id;
public UserRole(User user, Role role) {
this.user = user;
this.role = role;
}
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "user_id")
private User user;
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "role_id")
private Role role;
...
}
and want to print all the roles of a User, so I use this code:
<td class="col_name" th:text="${user.userRoles.role}"></td><!-- ROLES -->
but what I see in the browser is literally this:
com.tdk.backend.persistence.domain.backend.User.userRoles
You will want to iterate through the set of objects to print the role values. You can use Thymeleaf's th:each syntax to do so:
<td class="col_name">
<span th:each="userRole : ${user.userRoles}" th:text="${userRole.role}">[role]</span><!-- format with line breaks as needed -->
</td>
You can alternatively look at the lists utility and call the toString() to output for a quick and dirty way:
<td class="col_name">
<span th:text="${#lists.toString(user.userRole.role)}">[role]</span>
</td>
You can optionally remove the <span> tags by using th:remove="tag".

What is the EL test expression for foreign key attribute?

I have 3 entities :
#Entity
#Table(name = "resultat")
public class Resultat {
#Id
#SequenceGenerator(name="s_resultat", sequenceName="pta.s_resultat", allocationSize=1)
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="s_resultat")
#Column(name = "result_code")
private Integer code;
#Column(name="result_intitule")
private String lib;
#ManyToOne
#JoinColumn(name = "acti_code")
private Activite activite;
...
}
#Entity
#Table(name = "activite")
public class Activite {
#Id()
#Column(name="acti_code")
private String code;
#Column(name="acti_design")
private String lib;
#ManyToOne
#JoinColumn(name = "action_code")
private Action action;
public Activite() {
super();
}
...
}
#Entity
#Table(name = "action")
public class Action {
#Id
#SequenceGenerator(name="s_action", sequenceName="pta.s_action", allocationSize=1)
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="s_action")
#Column(name = "action_code")
private Integer code;
#Column(name="action_design")
private String lib;
...
}
Now I want to display a master-detail JSP page for the two entities Activite and Resultat. I created DAOs returning list of Action, list of Activite, and list of Resultat. And called them in the controller in order to be passed to the JSP.
In my JSP I loop the list of Activite first , then I loop the list of Resultat :
<c:forEach items="${activites}" var="activite" varStatus="statusActivite">
<c:forEach items="${resultats}" var="resultat">
// here I want to test if resultat is the right foreign key for the actual activite
</c:forEach>
</c:forEach>
So how to write the test for the resultat variable to be the foreign key associated to the activite ?

Spring 4 MVC Form: Create Object with list of sub objects

I looking for help in understanding how to create a new object through a form which has the user select multiple sub-objects (which will come pre-populated) and available to select with a checkbox.
OrderController.java
#RequestMapping(value = { "/order" }, method = RequestMethod.GET)
public String order(ModelMap model) {
List<Exam> exams = examService.findAllExams();
List<Document> documents = documentService.findAllDocuments();
model.addAttribute("exams", exams);
model.addAttribute("documents", documents);
return "order"; // jsp page reference
}
Order.java
#Entity
#Table(name="\"order\"")
public class Order implements Serializable
{
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "order_id", unique = true, nullable = false)
private Integer id;
#GeneratedValue(generator = "uuid")
#GenericGenerator(name = "uuid", strategy = "uuid2")
#Column(name = "uuid", unique = true, nullable = false)
private String uuid;
#Temporal(TemporalType.DATE)
#Column(name = "order_date", unique = true, nullable = false)
private Date orderDate;
#Column(name="order_status", nullable=false)
private String orderStatus;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "user_id", nullable = false)
private User user;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "order")
private Set<OrderExam> orderExams = new HashSet<OrderExam>(0);
#OneToMany(fetch = FetchType.LAZY, mappedBy = "order")
private Set<OrderDocument> orderDocuments = new HashSet<OrderDocument(0);
//getters & setters
}
OrderExam.java
#Entity
#Table(name="order_exam")
public class OrderExam implements Serializable
{
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "order_exam_id", unique = true, nullable = false)
private Integer id;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "order_id", nullable = false)
private Order order;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "exam_id", nullable = false)
private Exam exam;
#Column(name="exam_amount", nullable=true)
private Integer examAmount;
#Column(name="answer_sheet_amount", nullable=true)
private String answerSheetName;
#Column(name="students_per_csv", nullable=true)
private String studentsPerCSV;
#Column(name="pas", nullable=true)
private Boolean pearsonAnswerSheet;
//getters & setters
}
Exam.java
#Entity
#Table(name="exam")
public class Exam implements Serializable
{
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "exam_id", unique = true, nullable = false)
private Integer id;
#NotEmpty
#Column(name="name", unique=true, nullable=false)
private String name;
#NotEmpty
#Column(name="code", unique=true, nullable=false)
private String code;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "exam")
private Set<OrderExam> exams = new HashSet<OrderExam>(0);
//getters & setters
}
As you can see I am passing in a list of exams and documents which will populate a form with available options (can be seen in the image below (exams anyway)). The user needs to be able to select multiple rows, so that a single order has multiple exams and documents associated to it.
My order.jsp is a little much to post the entire thing here but here is the part I have which is displayed in the image above.
Order.jsp
<form:form method="POST" modelAttribute="order" class="form-horizontal form-label-left">
<c:forEach items="${exams}" var="exam">
<tr>
<th scope="row"><input type="checkbox" class="flat"></th>
<td><input id="middle-name" type="text" name="middle-name" readonly="readonly" value="${exam.name} - ${exam.code}" class="form-control col-md-7 col-xs-12"></td>
<td><input id="middle-name" type="text" name="middle-name" value="0" class="form-control col-md-3 col-xs-12"></td>
<td><input id="middle-name" type="text" name="middle-name" value="0" class="form-control col-md-3 col-xs-12"></td>
<td><input id="middle-name" type="text" name="middle-name" value="0" class="form-control col-md-3 col-xs-12"></td>
<c:choose>
<c:when test="${exam.name == 'Algebra 2 (Common Core)'}">
<th scope="row"><input type="checkbox" class="flat"></th>
</c:when>
<c:otherwise>
<th scope="row"></th>
</c:otherwise>
</c:choose>
</tr>
</c:forEach>
<!-- Other Stuff Goes Here -->
</form:form>
So in short, would someone be willing to show me how to set up the form in the way I described above? Thanks in advance.
Your question is a bit broad however you could try this as below. I have only covered exams. Principal for documents will be the same.
You will need a couple of new classes to capture the submitted form inputs:
Order Form to Capture Selections
public class OrderForm{
private List<ExamWrapper> allAvailableExams = new ArrayList<>();
private XOptionPrintWrapper selectedWrapper;
public OrderForm(){
}
//getters and setters
}
Exam Wrapper : Decorates an Exam with a 'selected' property
public class ExamWrapper{
private boolean selected;
private Exam exam;
public ExamWrapper(Exam exam){
this.exam = exams;
}
//getters and setters
}
Change Contoller to
public class OrderController{
//Exams model populated by the method below
//moved as we also need it populated on POST
#RequestMapping(value = { "/order" }, method = RequestMethod.GET)
public String order(ModelMap modelMap) {
//only needed on GET so put in model here
List<XOptionPrintWrapper> availableWrappers = //someList;
modelMap.put("availableWrappers", availableWrappers);
return "order";
}
//handles for submit
//model atribute is automatically populated by the framework
#RequestMapping(value = { "/order" }, method = RequestMethod.POST)
public String order(#ModelAttribute("orderForm") OrderForm orderForm) {
//process selected exams
return "nextView";
}
//on get populates the initial model for display
//on post create an instance which the form params will be bound to
#ModelAttribute("orderForm")
public OrderForm getOrderForm(){
OrderForm orderForm = new OrderForm();
List<Exam> exams = examService.findAllExams();
for(Exam exam : exams){
orderForm.getAllAvailableExams.add(new ExamWrapper(exam));
}
return orderForm;
}
}
In JSP use Sping support for binding to indexed properties:
<form:form method="POST" modelAttribute="orderForm" class="form-horizontal form-label-left">
<c:forEach items="${orderForm.allAvailableExams}" var="exam" varStatus="status">
<tr>
<th scope="row"><input name="allAvailableExams[${status.index}].selected"
type="checkbox" class="flat"></th>
</tr>
</c:forEach>
<form:select path="selectedWrapper">
<form:options items="${availableWrappers}"
itemValue="somePropertyOfXOptionPrintWrapper "
itemLabel="somePropertyOfXOptionPrintWrapper " />
</form:select>
</form>
I obviously haven't been able to try all of this but think it should all be okay.

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